Italy Prime Minister Silvio Berlusconi is under investigation for alleged sexual encounters with a 17-year-old girl. Officials are also investigating charges that he attempted to conceal the liaison.

Reporting from London — Italian prosecutors are investigating accusations that Prime Minister Silvio Berlusconi paid a 17-year-old girl for sex and abused the powers of his office by trying to cover up the liaison, officials said Friday.

The prime minister's lawyers quickly denied the allegations.

The public prosecutor's office in Milan said in a statement that it was investigating allegations that Berlusconi and Lombardy regional councilor Nicole Minetti attempted to conceal encounters between the prime minister and a then-underage Moroccan dancer known by the stage name Ruby Heartbreak. Police searched Minetti's office and home as well as sites tied to unnamed "other people" involved with the case, the prosecutors said.

Berlusconi is also suspected of trying to obtain the girl's release after she was arrested on theft charges in May, with his office reportedly falsely telling police that she was the granddaughter of Egyptian President Hosni Mubarak and that her detention would cause a diplomatic row.

The prosecution statement Friday said Berlusconi had been under investigation since Dec. 21 for alleged offenses committed between February and May of last year. The Italian newspaper Corriere della Sera reported that he had been summoned to appear in court between Jan. 21 and 23.

Berlusconi has denied having sex with the girl. His lawyers, Niccolo Ghedini and Piero Longo, called the accusations "absurd and groundless."

Though the age of sexual consent in Italy is 14, it is a crime to aid or exploit the prostitution of someone younger than 18.

The investigation was the latest scandal for the 74-year-old leader, who has faced accusations of bribery, tax fraud and sexual improprieties. It comes at a time his government has been struggling to remain in power after the defection last year of a key right-wing ally, Gianfranco Fini, who accused the prime minister of "moral decadence" and called for his resignation.

On Thursday, the Constitutional Court partially revoked a law pushed through by Berlusconi's supporters that postponed criminal trials of Cabinet members. The court ruled that it was up to judges in individual cases to decide whether a trial would constitute a "legitimate impediment" to ministerial duties and thus should be postponed for up to 18 months.

Karima El Mahroug, the now-18-year-old nicknamed Ruby, told Italian newspapers last year that she regularly went to parties in the Berlusconi villa at Arcore, outside Milan, and was paid $9,500 for attending. However, she denied ever having sex with the prime minister.

For his part, Berlusconi has never made a secret of his habit of throwing parties attended by models and nightclub dancers, answering critics with the statement: "I love life and beautiful women."

In 2009, Berlusconi's wife, Veronica Lario, instituted proceedings for legal separation from him after publicity surrounding his attendance at a birthday party held for an 18-year-old model named Noemi Letizia, saying she could not live with a man "who consorts with minors."

Berlusconi was already facing charges that he paid bribes in the 1990s to British lawyer David Mills to give false evidence in testimony on the billionaire's business deals. He also faces charges of tax fraud connected with his media interests. Trials in both cases were suspended after passage of the immunity law last year.